masquerading

To take part in a masquerade; to assemble in masks and costumes; to wear a disguise.

“I’m going to masquerade as the wikipede. What are you going to dress up as?”

To pass off as a different person or a person with qualities that one does not possess; also, to make a pretentious show of being what one is not.

“He masqueraded as my friend until the truth finally came out.”

To conceal (someone) with, or as if with, a mask; to disguise.

The act of one who masquerades.